CIL Rate Calculator UK
Calculate your statutory Community Infrastructure Levy (CIL) liability per square metre, apply BCIS All-in Tender Price Indexation, and check 100% self-build exemptions.
Statutory CIL Liability & Indexation Matrix
Base rate: £220/sqm + BCIS indexation (~38% inflation).
Gross Internal Area
Lawful in-use 6 of 36 months
£42,504
140 m²
CRITICAL DEADLINE WARNING: You must submit a CIL Form 6 Commencement Notice to the council before starting ANY work on site. Starting works without this form invalidates self-build relief and triggers an automatic 20% penalty surcharge.
The 4 Essential Rules of UK Community Infrastructure Levy (CIL)
Residential extensions under 100 square metres do not pay CIL. However, any development that creates a new self-contained dwelling (even a 35m² micro-flat) is legally chargeable from the first square metre.
CIL base rates are indexed annually using the Building Cost Information Service (BCIS) index. Rates set in 2015 can be 40% to 55% higher today, making indexation calculation essential.
Floorspace of existing buildings on site can be deducted from CIL if they have been in continuous lawful use for at least 6 months within the 36 months prior to planning permission.
Self-build relief is subject to a 3-year disqualifying event rule. If you sell or let the property within 36 months of completion, the full exempted CIL liability becomes immediately payable.
Frequently Asked Questions: Community Infrastructure Levy (CIL)
Statutory legal questions on CIL rates, BCIS indexation, and self-build relief.
The Community Infrastructure Levy (CIL) is a statutory planning charge introduced under the Planning Act 2008 and the Community Infrastructure Levy Regulations 2010. It enables local authorities in England and Wales to fund infrastructure—such as transport, flood defences, schools, and green spaces—by levying a non-negotiable charge on new developments that create 100 square metres or more of gross internal area (GIA), or create one or more new dwellings regardless of size.
Statutory Diligence Guides & Legal FAQs
Official regulatory answers referencing Acts of Parliament, RICS guidance, and statutory planning orders.
How Is CIL Charge Calculated in the UK? (Statutory Formula & Indexation)
Community Infrastructure Levy (CIL) is calculated using the statutory formula set out in Regulation 40 of the Community Infrastructure Levy Regulations 2010 (as amended): CIL Charge = (Gross Chargeable Area in m² × Adopted CIL Charging Schedule Rate £/m² × Indexation Factor for Planning Grant Year) ÷ Indexation Factor for Schedule Adoption Year. Chargeable area is calculated as the Net Additional Gross Internal Area (GIA), meaning the floorspace of existing permanent buildings demolished or converted can be deducted if they were in continuous lawful use for at least 6 months during the previous 3 years.
How to Calculate CIL Cost per Square Metre for New Developments
To calculate CIL cost per square metre: (1) Measure the Gross Internal Area (GIA) of the proposed development following the RICS Code of Measuring Practice (measuring to internal perimeter walls, including garages and basements), (2) Identify your local authority's CIL Charging Schedule map to determine your site's geographical charging zone (e.g. Zone 1 High vs Zone 3 Low), (3) Check the adopted base rate for your development use class (£/m²), and (4) Multiply the base rate by the current RICS CIL indexation factor (typically 1.45 to 1.65). In London, add the applicable Mayoral CIL (MCIL2) rate.
How Much Does CIL Cost in the UK? (Average Charges by Property Type)
Across England and Wales, the Community Infrastructure Levy (CIL) typically costs between £8,000 and £35,000 for a standard new-build 3-bedroom detached house (120–150 m²), rising to £50,000–£120,000+ per dwelling in prime London and affluent South East boroughs. For major residential developments, CIL liabilities range from £500,000 to £3,000,000+ depending on the charging zone. However, in low-viability northern and midland districts, many local authorities operate zero-rated (£0/m²) CIL policies to encourage housing delivery.
How Much Is Mayoral CIL in London? (MCIL2 Charging Bands & Rates)
Mayoral Community Infrastructure Levy 2 (MCIL2) is a statutory levy charged by the Greater London Authority (GLA) on all qualifying new developments across London to fund major transport infrastructure, including the Elizabeth Line and future transit networks. MCIL2 divides London into three charging bands: Band 1 (£80/m² in Camden, City of London, Kensington & Chelsea, Westminster, etc.), Band 2 (£60/m² in Barnet, Brent, Greenwich, Hackney, Richmond, etc.), and Band 3 (£25/m² in Barking & Dagenham, Bexley, Havering, Hillingdon, Newham, etc.). MCIL2 is charged in addition to individual London borough CIL rates.
CIL Rate per Square Metre Calculator Gov UK: Statutory Form Guide
The Gov.uk planning framework manages CIL through statutory Planning Portal forms rather than an online government calculation widget. To comply with statutory requirements: (1) Form 1 (CIL Additional Information) must accompany your initial planning application, detailing existing and proposed GIA in square metres, (2) Form 2 (Assumption of Liability) confirms who will pay the levy, (3) The council issues a statutory CIL Liability Notice upon granting permission, and (4) Crucially, Form 6 (Notice of Commencement) must be served on the council BEFORE any construction starts, or all surcharge penalties (up to £2,500) and loss of exemption rights occur.
How to Find Local Council CIL Charging Schedules in the UK
To find your local council's CIL Charging Schedule: (1) Visit your local planning authority's official website and navigate to Planning Policy > Community Infrastructure Levy, (2) Download their formal 'Adopted CIL Charging Schedule' document, (3) Inspect the geographical CIL Zone Map to determine whether your plot lies in a High, Medium, Low, or Zero charging band, and (4) Note the exact calendar adoption year, which determines the historical base indexation divisor. Alternatively, use our free online CIL Rate Calculator to look up adopted base rates and automatically compute indexed 2026 charges.
CIL Exemptions for Self-Build & Extensions: Statutory Rules & Form 7
Under Regulations 42A, 42B, 54A, and 54B of the CIL Regulations 2010 (as amended), self-builders and homeowners qualify for a mandatory 100% statutory exemption from CIL. For self-build dwellings, you must submit Form 7 Part 1 before commencing work and occupy the completed home as your sole or main residence for at least 3 continuous years. For domestic residential extensions exceeding 100 m² of GIA, you must submit Form 9 before commencement. Crucially, if you sell or let the property within 3 years of completion, the exemption is clawed back in full with interest.
Free Online CIL Rate Calculator UK: Instant Development Levy Estimator
Use our free online CIL Rate Calculator to model your exact statutory Community Infrastructure Levy liability in seconds. Enter your proposed Gross Internal Area (m²), deduct existing buildings eligible under the 6-in-36 month lawful use rule, select your local council and charging zone, and apply current RICS/BCIS indexation factors. The calculator automatically checks self-build exemption eligibility, calculates Mayoral CIL (MCIL2) for London sites, and outputs a certified 1-page A4 diligence brief for your planning consultant and lender.